1. Field of the Invention
The present invention relates generally to forming flexible metal pipe, and in particular to an apparatus for crimping the pipe ends.
2. Description of the Related Art
Flexible metal piping can be formed by spiral-winding a metal band on a rotating mandrel, with the band having a profile including flanges for interlocking adjacent pipe windings. For example, the McGowen U.S. pat. No. 4,197,728 discloses a flexible piping method and apparatus of producing same. Such flexible piping can be used in many applications, including the exhaust systems of some vehicles which require some flexibility. A pipe winding machine, such as that shown in the McGowen '728 patent can produce pipe sections of practically unlimited length and can produce pipe sections with various diameters.
Finishing the ends of the flexible pipe can require substantial effort and expense if the ends are deburred. When flexible pipes are cut, e.g. with plasma cutters, cutoff saws, etc., sharp burrs may be present on the pipe section ends. Such jagged, burred ends can be dangerous to people who handle the flexible pipe sections, particularly if they neglect to wear protective gloves. Lacerations and similar injuries can be inflicted by such pipe ends, which can also damage property that they are exposed to.
To avoid some of these risks, flexible pipe sections can be deburred with grinding wheels, files, etc., but such deburring operations tend to be labor intensive and expensive in relation to the cost of the flexible piping.
The McGowen '728 patent discloses a shaping tool for altering the profile of the band to a noninterlocking configuration whereby a free winding is formed with crimped pipe section ends on either side. The present invention performs a similar function with an improved crimping apparatus, and addresses some of the aforementioned problems.